Maldives Desalination Facility Records Net Energy Gain

Operating data from an installation of seawater desalination units that employ memsys’ membrane distillation technology indicates a significant net gain in energy production from the diesel generators that power the system. memsys, a Singaporean-German company, pioneered the technology, which is based on vacuum multi-effect membrane distillation (V-MEMD), a highly efficient thermal process for thermal separations in a modular concept.

“I believe that memsys is the first company to create a symbiotic rather than parasitic relationship between diesel-powered electricity generation and desalination. I call this ‘energy positive desalination’. It represents a breakthrough in the way we think about desalination and will have a very positive economic and environmental impact in locations throughout the world where the memsys desalination technology is coupled with similar diesel-powered electricity generators,” said Florian Bollen, a director of memsys.

“We have run the plant for more than three months now on the remote island of Gulhi on the Maldives, under 24/7 operations and with more than 99% uptime. It was a pleasant surprise to us when the numbers showed an increase of generator fuel efficiency of more than 10% while the desalination plant only consumes about 2% of the electrical output — giving this combination a positive result on power creation while desalinating water,” Bollen added.

The memsys desalination process is driven primarily by the heat it harvests from the cooling of the generators and eliminates the need for parasitic loads like fans. In addition, the cooling through water is efficient even at high ambient temperatures, allowing the generator to run on high loads rather than spreading the load onto separate generators running less efficiently at lower loads. It also allows the operator to turn off the fans that usually blow air towards the cooling radiators of the generator. This gives the generators an efficiency boost that is much greater than the electrical consumption of the desalination plant, which is driven mostly by the heat gained from the cooling of the generator.

The net result is an overall reduction in fuel consumption for the same amount of power generation while at the same time desalinating water.

The Maldivian state electricity company STELCO stated, “This memsys innovation has huge implications for us. We are very pleasantly surprised by memsys’ technology. At first, we expected a cheaper and more reliable way to desalinate water than traditional desalination technologies. Now we see the memsys system as an easy way to also slash our energy costs while producing clean water. Clean water and low energy costs are equally important priorities in the Maldives.”